Grading Standards and Gem Quality Information

The 4 – C’s of Gemstones – A stone’s color, clarity, cut and carat weight. The explanations below are base
on the system of evaluation established by the Gemological Institute of America (GIA). For more information on the
GIA, please visit www.gia.edu.

Color: Is typically the most important value-setting factor of gemstones. All gems have a preferred color or
a small range of preferred colors. The more the color varies from this range the less valuable the stone.
Color is composed of three dimensions: hue, tone, and saturation. Hue refers to the impression of color
usually noticed immediately, such as red, yellow or green. Tone refers to the degree of lightness or darkness of
an object. Saturation defines the degree of purity of a hue.

Cut: Cut refers to the shape or design of a stone, arrangement of facets, as well as the overall symmetry or
proportions and the degree of finish or polish. A well-proportioned, meetpoint faceted cut with a superb polish
will elicit and take full advantage of the gemstone’s optical properties.

Carat Weight: Gemstones are weighed in of the metric carat. The metric carat is equal to 0.2 of a
gram. Although most commonly associated with Diamonds, the metric carat can be further subdivided into hundredths
of a carat or in trade language – points. A quarter of a carat (0.25 ct) is the same as 25 points.

Clarity: A gemstone’s clarity grade is directly related to its rarity. Clarity refers to a gemstone’s
relative freedom from clarity characteristics. Clarity characteristics include inclusions (lie within the stone) or
blemishes (lie on the surface of the stone). The fewer clarity characteristics, the rarer the gemstone is. Each
variety has its own clarity standards. For this reason, the GIA’s grading system divides transparent colored
gemstones into three clarity types. This allows the gems to be more evenly evaluated, as it takes into account
the individual nature of each gemstone. Each type is further sub-divided into five grading descriptions.

Enhancement: Any traditional process other than cutting and polishing that improves the appearance (color/clarity/phenomena), durability, or availability of a gemstone.

N – The “N” symbol appears only for natural stones which are not currently known to be enhanced; however, the N symbol can also be used for other natural gemstones in the event that a gemstone has received no enhancement and the
seller will provide a guarantee that there has been none.

E – The “E” symbol indicates that the gemstone has undergone its traditional enhancement process.

Symbols for Specific Form of Enhancement

Bleaching (B): The use of heat, light, and/or other agents to lighten or remove a gemstone’s color.

Coating (C): The use of such surface enhancements as lacquering, enameling, inking, foiling, or sputtering of films to improve appearance, provide color, or add other special effects.

Dyeing (D): The introduction of coloring matter into a gemstone to give it new color, intensify present color or improve color uniformity.

Heating (H): The use of heat to effect desired alteration of color, clarity, and/or phenomena. If residue of foreign substances in open fissures is visible under properly illuminated 10X magnification HF should be used.

Heat & Pressure (HP): The use of heat and pressure combined to effect desired alteration of color, clarity and/or phenomena.

Impregnation (I): The impregnation of a porous gemstone with a colorless agent (usually plastic) to improve durability and appearance.

Oiling/Resin Infusion (O): The filling of surface-breaking fissures with colorless oil, wax, resin, or other colorless substances, except glass or plastic, to improve the gemstone’s appearance.

Irradiation (I): The use of neutrons, gamma rays or beta particles (high energy electrons) to alter a gemstone’s color. The irradiation may be followed by a heating process.

Diffusion (U): The use of chemicals in conjunction with high temperatures to produce artificial color and/or asterism-producing inclusions.

Waxing/Oiling (W): The impregnation of a colorless was, paraffin, and oil in porous opaque or translucent gemstones to improve appearance.

Quality Criteria by Mineral Type

The following list is by no means all inclusive and will be updated as grading standards are revised by generally accepted trade practices. To the best of Mainely Gems ability, every mineral or material that is purchased will have full disclosure to the Four C’s and any treatments or enhancements from its natural state.